References made throughout this specification are grouped together below. Reference is cited by author [Number], e.g. Aruga [1]:    1. Aruga, T., 1997, “Generation of long-range nondiffracting narrow light beams,” Appl. Opt., Vol. 36, 3762-3768 (1997).    2. Aruga, T., S. W. Li, 1999, “Super high resolution for long-range imaging,” Appl. Opt. Vol. 38, 2795-2799.    3. Aydin, K., I. Bulu, E. Ozbay, 2005, “Focusing of electromagnetic waves by a lefthanded metamaterial flat lens,” 31 Oct. 2005/Vol. 13, No. 22/OPTICS EXPRESS 8753    4. Belov, P. A., M. G. Silveirinha, 2006a, “Resolution of sub-wavelength transmission devices formed by a wire medium, Phys. Rev. B 73, 033108 (2006), arXiv: cond-mat/0610558v1    5. Belov, P. A., Y. Zhao, S. Sudhakaran, A. Alomainy, Y. Hao, 2006b, arXiv:cond-mat/0610558v1 19 Oct. 2006    6. Cubukcu, E., K. Aydin, E. Ozbay, S. Foteinopoulou, and C. M. Soukoulis, 2003a, “Electromagnetic waves: Negative refraction by photonic crystals,” Nature 423, 604 (2003).    7. Cubukcu, E., K. Aydin, S. Foteinopolou, C. M. Soukoulis, and E. Ozbay, 2003b, “Subwavelength resolution in a two-dimensional photonic crystal based superlens,” Phys. Rev. Lett. 91, 207401 (2003).    8. Dolling, G., M. Wegener, C. M. Soukoulis, S. Linden (2007) Vol. 32 pp. 53-55, Optics Letters “Negative-index metamaterial at 780 nm.”    9. Dolling, G., C. Enkrich, M. Wegener, C. M. Soukoulis, S. Linden, (2006a) Science, Vol. 312, p. 892    10. Dolling, G., C. Enkrich, M. Wegener, C. M. Soukoulis, S. Linden, (2006b) Opt. Lett., Vol 31, p. 1800    11. Durnin, J. 1987, “Exact solution for nondiffracting beams I: the scalar theory,” J. Opt. Soc. Am. A Vol 9, pp. 651-654 (1987).    12. Durnin, J. Miceli, Jr., J. H. Eberly, “Diffraction-free beams,” Phys. Rev. Lett., Vol. 58, 1499-1501 (1987).    13. Z. Jiang, Q. Lu, and Z. Liu, “Propagation of apertured Bessel beams,” Appl. Opt. 34, 7183-(1995)    14. Luo, C., S. G. Johnson, J. D. Joannopoulos, and J. B. Pendry, 2002, “All-angle negative refraction without negative effective index” Phys. Rev. B 65, 201104(R) (2002).    15. Notomi, M., 2000, “Theory of light propagation in strongly modulated photonic crystals: Refraction like behavior in the vicinity of the photonic band gap,” Phys. Rev. B 62, 10696 (2000).    16. Parimi, P. V., W. T. Lu, P. Vodo, and S. Sridhar, 2003, “Imaging by flat lens using negative refraction,” Nature 426, 404 (2003).    17. Pendry, J. B., A. J. Holden and W. J. Stewart I. Youngs, (1996) Extremely Low Frequency Plasmons in Metallic Mesostructures, Vol. 76, Number 25, Physical Review Letters, 17 Jun. 1996.    18. Pendry, J. B., A. J. Holden, D. J. Robbins, and W. J. Stewart, (1999) “Magnetism from Conductors and Enhanced Nonlinear Phenomena,” IEEE Transactions on Microwave Theory and Techniques, vol. 47, no. 11, November (1999). 2075.    19. Pendry, J. B., (2000) “Negative Refraction Makes a Perfect Lens,” Phys. Rev. Lett. 85, 3966 (2000).    20. Pendry, J. B., D. Schurig, D. R. Smith, 2006, “Controlling Electromagnetic Fields,” Science, Vol. 312, pp. 1780-1782.    21. Pimenov, A., Loidl, K. Gehrke, V. Moshnyaga, K. Samwer, 2007, “Negative Refraction Observed in a Metallic Ferromagnet in the Gigahertz Frequency Range, Physical Review Letters, Vol. 98, p. 197401 (2007).    22. Shalaev, V. M., W. CAI, U. K. Chettiar, H.-K. Yuan, A. K. Sarychev, V. P. Drachev, and A. V. Kildishev, (2005) “Negative index of refraction in optical metamaterials,” Opt. Lett. 30, 3356-3358 (2005).    23. Shelby, R. A., D. R. Smith, and S. Schultz: Experimental Verification of a Negative Index of Refraction” Science 292, 77-70 (2001).    24. Smith, D. R. S. Schultz, P. Marcos, and C. M. Soukoulis, “Determination of effective permittivity and permeability of metamaterials from reflection and transmission coefficients., Phys. Rev. B65, 195104 (2002)    25. Synge E H, 1928, A suggested method for extending microscopic resolution into the ultra-microscopic region. Phil Mag 6, 356-362 (1928)    26. Uday K. Chettiar, Alexander V. Kildishev, Thomas A. Klar†, and Vladimir M. Shalaev, “Negative index metamaterial combining magnetic resonators with metal films”    27. Veselago, V., G., 1968, “The electrodynamics of substances with simultaneously negative values of ∈ and μ.” Soviet Physics USPEKI 10, 509-514    28. Wiley, B. J., Y. Chen, J. McLellan, Y. Xiong, Z-Y Li, D. Ginger, Y. Xia, 2007, “Synthesis and Optical Properties of Silver Nanobars and Nanorice,” Nano Letters, Vol. 0, No. 0, A-E, American Chemical Society, Published on Web Mar. 8, 2007    29. Zhang, S., W. Fan, N. C. Panoiu, K. J. Malloy, R. M. Osgood and S. R. J. Brueck, 2005, “Demonstration of Near-Infrared Negative Index Metamaterials,” Phy. Rev. Lett. 95, 137404.    30. Zhang, S., W. Fan, N. C. Panoiu, K. J. Malloy, R. M. Osgood and S. R. J. Brueck, 2006, “Optical negative-index bulk metamaterials consisting of 2D perforated metal-dielectric stacks    31. Zhao, Y., P. A. Belov, Y. Hao, 2006, “Spatially dispersive finite-difference time-domain analysis of sub-wave-length imaging by the wire medium slabs,” arXiv: physics/06605025v1 3 May 2006.
Microstructures such as cancer cells have as lower limit the cells of their normal matrix (e.g., breast tissue). Brain neuron axons have characteristic diameters of 8 μm to 80 μm. Animal virus dimensions range from poliomyletis (30 nm) to vaccinia (230 nm). Originally Koch and Pasteur, in the second half of the 18th century studied certain microstructures (e.g., anthrax) with electromagnetic means, namely light, in the visible wavelength range about 200 nm-800 nm (i.e., 2000-8000 Å). The difficulty with applying these wavelengths is that they only detect the presence of microstructure (e.g., cancer cells from a biopsy or, anthrax spores on the surface of a letter or package), within the limits of the penetrability of visible light, e.g. on or near surface locations.
Probing into structures is easier using a relatively longer wavelength. Such electromagnetic radiation (e.g., millimeter or centimeter wavelength microwaves) will penetrate letters and packages.
One difficulty, however, with longer wavelengths is the mismatch with the size of the objects they are trying to detect. The ordinary limit of smallest features detectable by electromagnetic wavelength λ is approximately of the order of that wavelength, λ. The Abbe-Rayleigh theory (Born and Wolf, 2nd edition, p. 333 ff, p. 420 ff) expresses the discernable dimension separation between two interfering electromagnetic radiation waves as λ with some additional numerical factors of the order of unity which may depend upon the coherence of the light and on the geometry of the object for which the dimensional resolution is sought.
The near field effect of using small apertures, i.e., λ>>a, where a is the aperture radius, have been successfully used to increase resolution beyond the Abbe-Rayleigh limit. Ash and Nicholls, for the near field, (Nature, 237, pp. 510-512, 1972) demonstrated a spatial resolution of several millimeters at λ=3 cm using a 1.5 mm diameter circular aperture in a conducting screen. Golosovsky and Davidov, (Appl. Phy Lett., 68 (11), 1996, pp. 1579-1581) also used the near-field for microwave imaging. In contrast to Ash and Nicholls, however, they used a narrow resonant slit (instead of a circular aperture) to achieve a high transmission coefficient (in a limited frequency range) compared to the circular aperture. They were able to get a resolution of 70 μm-to 100 μm at 80 GHz (λ=3.75 mm). The resolution was therefore about λ/50. Knoll and Keilmann (Nature, 399, pp. 134-137, 1999) used an antenna tip to act as a scattering center. The investigation was done in the infrared and achieved a near-field resolution of 100 nanometers, about λ/100. A scattering tip was actually used in place of an aperture.
First attempts to initiate confined beams ran up against energy conservation. Basically, a beam on some enclosing spherical surface at radius R1 intersects the sphere of R1 with a finite area of π∈2, where ∈ is the radius of the small spot illuminated on the interior surface of the enclosing sphere with radius R1. For a constant energy source, the energy density of the spot on an enclosing sphere of R2 is (R1/R2)2π∈2, where R2>>R1. The only way to soup-up the energy density is to supply more energy to the beam. As R2 goes toward infinity, an infinite amount of energy would have to be confined by the beam.
However, Durbin (1987), Durnin, et al. (1987), however, found that a beam with a considerable depth of field could effectively be confined in radial direction. These are typically referred to as “Bessel beams”, or “quasi-non-diffracting beams” or similar.
As a more simple construction, photonic crystals showed a band structure with a negative dispersion which gave rise to an effective negative index of refraction. See, for example, Aydin and Bulu (2005), Luo (2002) Notomi (2000), E. Cubukcu (2003a, 2003b), and Parimi (2003). Typical photonic crystals are composed of a three dimensional array of metal or dielectric wires/tubes which are arranged with symmetry in two dimensions, the third dimension being the axis parallel to the (finite) lengths of wires.
As another example, Aruga (1997), Aruga, et al. (1999), showed a “long-range non-diffracting” beam with a 10 cm diameter telescope at 1 km, with an improvement over diffraction-limited optics: measured by: (width of ordinary Bessel beam)/(width of ordinary beam)=0.72. Aruga used a telescope objective with a spherical aberration to produce the Bessel beam.
Magnetic resonance imaging with a minimum resolution around 0.1 to 0.01 mm has been used to visualize the structure of a brain, before surgery on that brain. The brain may change shape after an incision because the pressure of the spinal-cephalic fluid may change. There are also other naturally occurring movements of the brain with time. While a patient may have additional magnetic resonance scanning done during the surgery, the results are not simultaneous with the surgery and often may be difficult to perform during a hiatus in the brain surgery.
One aspect in achieving a diagnostic/treatment tool/method/apparatus is to produce a “narrow,” i.e., a beam elongated in its direction of propagation (e.g., “z”), while limited in it other dimensions, for example in the other two dimensions (“x” and “y,” for a Cartesian coordinate system).
As an aid in better defining a beam, an apodizer may be utilized. (Jiang, et al., 1995).
An additional requirement exists for the practical utilization of a diagnostic/treatment apparatus, namely, the steerability of the beam.
In an MRI, for example, a patient may be moved repeatably into and out of a magnetic field scanning region, or, as in a CAT (computer aided tomography) scan, a scanning X-ray unit may mechanically progressively revolve around and along a patient.
While it is possible to mechanically move the beam, or the subject of the inspection, a better solution is to move the beam. A need exists for a system, method and apparatus which can detect cancer cells while there are relatively few of them, and, with additional capability for ablating detected cancer cells. A pertinent element in such an apparatus may be an electronically steerable narrow beam.
Metamaterial is defined, for example, in reference 20, [Controlling Electromagnetic Fields, J. B. Pendry, D. Schurig, D. R. Smith, Science 312, 1780 (2006)]: “A new class of electromagnetic materials (1, 2) is currently under study: metamaterials, which owe their properties to Subwavelength details of structure rather than to their chemical composition, can be designed to have properties difficult or impossible to find in nature.”